Malolactic cultures are bacteria that convert harsher malic acid to lactic acid. They are often used in red wines to mellow them and sometimes in Chardonnay and Sauvignon Blanc to provide buttery notes. This culture is added 2-3 days into the initial ferment while the alcohol levels are lower. This was the original Malo-lactic strain that most winemakers used. One packet will inoculate up to 66 gallons!